Luke de Pulford is a political adviser. He lives and works in Westminster.

Finally the International Community is waking up to ISIS’s bloody rampage in Northern Iraq. Until this point, with the notable exception of France, the world’s governments and media have kept an unconscionable silence.

And what were they ignoring? More than two months ago, the city of Mosul was emptied of its Christians. According to reports, there is not a single Christian left in Mosul, a town which once had a thriving Christian population of 60,000. Residents were told to convert to Islam or face the sword after the offer to pay heavy taxes expired in mid-July.

It’s a similar story in Qaraqosh, a Christian town of 50,000, whose residents have fled to Kurdistan or further afield in an effort to avoid being butchered by ISIS’s death-crazed fanatics. As I write, the Yazidi community wait atop Mount Sinjar for death either by dehydration or at the hands of an ISIS machete.

If you think that language hyperbolic, see how you feel after you have seen this, this or this (warning: extremely graphic images) or watch this interview with a Chaldean Christian who reports: “children are being beheaded, mothers are being raped and killed, and fathers are being hung.”

Amazingly, more than two months after Mosul, and despite encouragement from the Iraqi Government, Middle-Eastern bishops, British MPs and even the recently retired former Head of Policy at the Foreign Office, no one – not a single solitary voice – at the Foreign Office itself has thought the situation serious enough to condemn by name the ongoing massacre and expulsion of Christians from Mosul or Qaragosh.

Here are some reasons that the Foreign Office must develop a much more robust response, and soon.

Estimates are that up to 700 UK citizens are fighting for ISIS. These UK citizens are amongst those who are attempting to cleanse Iraq of its religious minorities. Some of their number could be beheading children, if reports of that practice are to be believed. If the UK Government does not have an opinion on its citizens beheading religious minorities in other countries, then it really ought to pack up and go home.

This crisis is partly of our own making. Like it or not, we contributed to the political instability of Iraq, which has enabled ISIS to occupy huge swathes of the country. Academics and commentators will argue about to what extent the coalition invasion of Iraq catalysed the rise of ISIS. At the very least, we have to admit some responsibility for the swiftness and efficiency with which ISIS has been able to command control of so much of Iraq, taking advantage of the war-weakened or embryonic infrastructure in order to impose their murderous caliphate. We cannot turn a blind eye to suffering that we have played a major part in enabling.

Action is needed to quiet the increasingly legitimate criticism that the Foreign Office has a problem denouncing human rights abuses against Christians. Even now, months after the systematic expulsion and killing of Christians began in Mosul, no specific condemnation has been forthcoming. Until Tobias Ellwood’s slightly better statement on Thursday (which still fails to acknowledge overwhelmingly predominant anti-Christian violence in Mosul and Qaragosh), the only line on this was a deeply pathetic, politically correct tweet from Hugo Swire last month which is worth quoting in all its vacuous glory:

“FCO Orals exchange on freedom of religion. Persecution not limited to single region or faith. UK challenging intolerance from #Sudan to #DPRK”.

Christians are apparently now the most persecuted people on earth. What manner of depravity needs to afflict Christians in northern Iraq before officials at the Foreign Office see fit to denounce it by name? Following America’s lead, we have been quick to condemn the awful humanitarian crisis of the Yazidis. Why not the months of predominantly anti-Christian slaughter that preceded it?

The Foreign Office needs to justify its cost and operational breadth. We keep hearing about the pride with which it cherishes the reach of its diplomatic service, comprising at least 280 posts. Yet it was not until Obama had announced airstrikes and the BBC had reported on the President’s statement that any decent comment could be extracted from our Government about Iraq’s summer of unimaginable, depraved cruelty. One could be forgiven for wondering who is leading the Foreign Office, or why on earth we are maintaining this service, at great cost, if its statements and action are going to be dictated to by the top three stories on BBC News, two months after a full-blown humanitarian crisis has become apparent? These questions ought to give rise to some serious reflection in King Charles Street. I sincerely hope that they have already occurred to Philip Hammond.

Lastly, there is an opportunity to give some substance to the claim that “values underpin our foreign policy”, as the Foreign Office never tires of saying. This grandiose claim might have a little more credibility if we were to show some basic human decency to Iraqis who face conversion or the sword by following France’s lead in offering them political asylum. In a tragedy of this scale and severity, anything less is an extension of the shameful silence which, so far, has characterised the UK’s response.

Like Rwanda, Srebrenica and Cambodia, Iraq in 2014 will be remembered both for unspeakable crimes against humanity and the failure of international governments to prevent catastrophic loss of life. The UK now has to decide which side of history it wants to be on, for the sake of the Iraqi people.